code: def __getitem__(self, idx):
      return self.data_index[idx], self.data_label[idx]
  
file_path: PGL/examples/gnn_depoly/node_classification_with_sampling/dataset.py
imports: import numpy
  import paddle
  from paddle.io import Dataset, DataLoader
  from pgl.sampling import graphsage_sample
label_desc: Use image node_id 2 for calling the ShardedDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: self,  self